Qinling Mountains are regarded as the dragon vein of Chinese civilization. The main peak of Taibai Mountains is 3771.2 meters high. It is located in Baoji City, Shaanxi Province. Qinling Mountain is the boundary between Neiguanzhong Plain and southern Shaanxi Province. Qinling Tunnel, once the longest railway tunnel in China, is situated between Qingcha Station and Yingpan Station of Xi'an (An) Kang Railway. It consists of two basically parallel single-track tunnels with a distance of 30 meters, of which the length of Line I tunnel is 18460 meters and the length of Line II tunnel is 18456 meters.